1. Everything that has life – from humans to plants to animals to birds to microorganisms – everything is made of cells. Some living organisms can be single-celled while some are multicellular. For example, bacteria are single-celled organisms while trees, birds, animals, humans – they are all multicellular organisms.

5. The first ever cell that originated on Earth was a Prokaryotic cell. Eukaryotic cells later evolved from the Prokaryotic cells.

7. Here is something really interesting that you should know. The size of a cell is usually determined by its diameter and not by the length. The usual size of a typical cell in human body can range anywhere between 10 µm and 100 µm (µm stands for micron, which is 1 millionth of a meter or 1 thousandth of a millimeter).Play Video

8. The largest cell in human body is approximately 120 µm. It is the female mature egg and the smallest cell in human body is the spermatozoon’s head with the size of 5 µm.